Increasing the productivity of TNFR-Fc in GS-CHO cells at reduced culture temperatures

Abstract

In an effort to improve TNFR-Fc production in GS-CHO cells, batch cultures were performed to investigate the effects of low culture temperature on TNFR-Fc production. It was observed that low culture temperatures resulted in cell cycle arrest in the G1 phase, led to suppressed cell growth, and prolonged the culture period. Although the highest TNFR-Fc concentration was achieved with a culture temperature of 32°C at 247.4 mg/L, the maximum q TNFR-Fc of 15.7 pg/cells/day was achieved at 30°C. Because the inhibition effect on cell growth at 30°C compromised its beneficial effects specifically to TNFR-Fc productivity, TNFR-Fc concentration at this temperature was not significantly increased. Furthermore, the increase in productivity of specific TNFR-Fc at low culture temperatures was also found to be due to an increase in the transcriptional level of the TNFR-Fc gene, determined by RT-PCR analysis. In addition, low culture temperatures had no significant effect on the degree of sialylation of TNFR-Fc. Taken together; a biphasic cultivation process developed in a fed-batch mode with a low temperature-production phase enhanced TNFR-Fc production by GS-CHO cells and therefore offers major potential for bioprocess optimization.